Mutations in the SYP gene (Xp11.23-p11.22) cause SYP-related mental retardation. In 1122 individuals with X-linked intellectual disability, four different mutations were identified in the SYP gene. SYP encodes an intergral membrane protein of small synaptic vesicles.
For patients with suspected SYP-related X-linked mental retardation, sequence analysis is recommended as the first step in mutation identification. For patients in whom mutations are not identified by full gene sequencing, deletion/duplication analysis is appropriate.
- OMIM #300653: Mental Retardation, X-Linked, SYP-Related.
- OMIM #313475: Synaptophysin.
- Tarpey et al. A systematic, large-scale resequencing screen of X-chromosome coding exons in mental retardation. Nature Genetics 2009; 41:535-543.
- Confirmation of a clinical diagnosis of SYP-related X-linked mental retardation in an individual in whom sequence analysis was negative.
- Carrier testing in adults with a family history of SYP-related X-linked mental retardation in whom sequence analysis was negative.
Please note that a "backbone" of probes across the entire genome are included on the array for analytical and quality control purposes. Rarely, off-target copy number variants causative of disease may be identified that may or may not be related to the patient's phenotype. Only known pathogenic off-target copy number variants will be reported. Off-target copy number variants of unknown clinical significance will not be reported.
Submit only 1 of the following specimen types
Preferred specimen type: Whole Blood
Type: Whole Blood
Specimen Requirements:In EDTA (purple top) or ACD (yellow top) tube:
Infants (<2 years): 2-3 ml
Children (>2 years): 3-5 ml
Older Children & Adults: 5-10 ml
Specimen Collection and Shipping: Refrigerate until time of shipment. Ship sample within 5 days of collection at room temperature with overnight delivery.
Specimen Requirements:OrageneTM Saliva Collection kit (available through EGL) used according to manufacturer instructions.
Specimen Collection and Shipping: Store sample at room temperature. Ship sample within 5 days of collection at room temperature with overnight delivery.
Sequence analysis is required before deletion/duplication analysis by targeted CGH array. If sequencing is performed outside of Emory Genetics Laboratory, please submit a copy of the sequencing report with the test requisition.
- Sequence analysis of the SYP gene is available and is required before deletion/duplication analysis.
- Custom diagnostic mutation analysis (KM) is available to family members if mutations are identified by targeted mutation testing or sequencing analysis.
- Prenatal testing is available only for known familial mutations to individuals who are confirmed carriers of mutations. Please contact the laboratory genetic counselor to discuss appropriate testing prior to collecting a prenatal specimen.